ORIGINAL PAPER Molecular cloning, purification and characterisation of myosin of human lymphatic filarial parasite Brugia malayi S. K. Verma & I. Bansal & S. Vedi & J. K. Saxena & V. M. Katoch & S. M. Bhattacharya Received: 31 July 2007 / Accepted: 30 October 2007 / Published online: 7 December 2007 # Springer-Verlag 2007 Abstract Global efforts have been made towards develop- ment of vaccine for prevention of lymphatic filariasis. However, lack of thorough knowledge about developmental biology and pathogenesis of filarial parasite restricts us from developing an effective vaccine. A limited number of immunodominant antigens of human lymphatic filariid Brugia malayi have been characterised; however, none of these recombinant antigens so far induced significant degree of protective immunity to challenge infection. In the present study, we identified a ~2.0 Kb cDNA clone by immuno- screening of cDNA library of adult female Brugia malayi. The nucleotide sequence of the identified clone showed 94.3% homology with C-terminal part of myosin heavy chain gene of Brugia malayi. This cDNA insert was sub- cloned into pET28b vector and expressed in BL21(DE3). The recombinant protein was purified to near homogeneity by immobilised metal affinity chromatography (IMAC) with yield of ~25 mg/l. The purified protein was recognised in western blot with anti-His tag antibody as also with the antibodies present in the sera of human W. bancrofti patients of all categories and infected/immunized rodent serum demonstrating its functional role. Recombinant myosin induced marked cellular immune response as observed by lymphoproliferation assay. The present findings demon- strate the usefulness of B. malayi recombinant myosin as vaccine candidate against human lymphatic filariasis. Introduction Lymphatic filariasis (LF), a major tropical disease caused by mosquito-borne nematode parasites, is a major cause of clinical morbidity and an impediment to socioeconomic development. It is the world’ s second leading cause of per- manent long-term disability, and its prevalence is increasing due to fast urbanisation and unplanned growth of cities (W.H.O. 1992). Approximately 120 million people are estimated to be infected with human lymphatic parasites Wuchereria bancrofti, Brugia malayi and Brugia timori (Michael et al. 1996), and India alone accounts for ~38% of the global disease burden (Ramaiah et al. 2000). Numerous studies performed over the past 25 years have shown that certain degree of protective immunity to filariasis can be produced in jirds, dogs and monkeys by vaccination with irradiated filarial larvae (Wong et al. 1974; Chusattayanond Parasitol Res (2008) 102:481–489 DOI 10.1007/s00436-007-0786-2 S. K. Verma : S. Vedi : S. M. Bhattacharya (*) Division of Parasitology, Central Drug Research Institute, Post Box 173, Chattar Manzil Palace, Lucknow 226001, Uttar Pradesh, India e-mail: Shailja_cdri@rediffmail.com I. Bansal : J. K. Saxena Division of Biochemistry, Central Drug Research Institute, Post Box 173, Chattar Manzil Palace, Lucknow 226001, Uttar Pradesh, India V. M. Katoch Department of Microbiology and Molecular Biology, Central JALMA Institute for Leprosy (ICMR) and Other Microbial Diseases, Tajganj, Agra 282001, Uttar Pradesh, India Present address: S. K. Verma DRDE, Gwalior 474002, Madhya Pradesh, India